Added `sd_imageFrameCount` convenient API for UIAinmatedImage/NSBitmapImageRep

Fix one issue when input UIAnimatedImage contains only 1 image

SDWebImage/Core/SDImageCoderHelper.m

@@ -135,7 +135,6 @@ static const CGFloat kDestSeemOverlap = 2.0f;   // the numbers of pixels to over
         avgDuration = 0.1; // if it's a animated image but no duration, set it to default 100ms (this do not have that 10ms limit like GIF or WebP to allow custom coder provide the limit)
     }
     
-    __block NSUInteger index = 0;
     __block NSUInteger repeatCount = 1;
     __block UIImage *previousImage = animatedImages.firstObject;
     [animatedImages enumerateObjectsUsingBlock:^(UIImage * _Nonnull image, NSUInteger idx, BOOL * _Nonnull stop) {
@@ -149,15 +148,12 @@ static const CGFloat kDestSeemOverlap = 2.0f;   // the numbers of pixels to over
             SDImageFrame *frame = [SDImageFrame frameWithImage:previousImage duration:avgDuration * repeatCount];
             [frames addObject:frame];
             repeatCount = 1;
-            index++;
         }
         previousImage = image;
-        // last one
-        if (idx == frameCount - 1) {
-            SDImageFrame *frame = [SDImageFrame frameWithImage:previousImage duration:avgDuration * repeatCount];
-            [frames addObject:frame];
-        }
     }];
+    // last one
+    SDImageFrame *frame = [SDImageFrame frameWithImage:previousImage duration:avgDuration * repeatCount];
+    [frames addObject:frame];
     
 #else
     

SDWebImage/Core/UIImage+Metadata.h

@@ -20,12 +20,23 @@
  * For animated image format, 0 means infinite looping.
  * Note that because of the limitations of categories this property can get out of sync if you create another instance with CGImage or other methods.
  * AppKit:
- * NSImage currently only support animated via GIF imageRep unlike UIImage.
- * The getter of this property will get the loop count from GIF imageRep
- * The setter of this property will set the loop count from GIF imageRep
+ * NSImage currently only support animated via `NSBitmapImageRep`(GIF) or `SDAnimatedImageRep`(APNG/GIF/WebP) unlike UIImage.
+ * The getter of this property will get the loop count from animated imageRep
+ * The setter of this property will set the loop count from animated imageRep
  */
 @property (nonatomic, assign) NSUInteger sd_imageLoopCount;
 
+/**
+ * UIKit:
+ * Returns the `images`'s count by unapply the patch for the different frame durations. Which matches the real visible frame count when displaying on UIImageView.
+ * See more in `SDImageCoderHelper.animatedImageWithFrames`.
+ * Returns 1 for static image.
+ * AppKit:
+ * Returns the underlaying `NSBitmapImageRep` or `SDAnimatedImageRep` frame count.
+ * Returns 1 for static image.
+ */
+@property (nonatomic, assign, readonly) NSUInteger sd_imageFrameCount;
+
 /**
  * UIKit:
  * Check the `images` array property.

SDWebImage/Core/UIImage+Metadata.m

@@ -29,6 +29,27 @@
     objc_setAssociatedObject(self, @selector(sd_imageLoopCount), value, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
 }
 
+- (NSUInteger)sd_imageFrameCount {
+    NSArray<UIImage *> *animatedImages = self.images;
+    if (!animatedImages || animatedImages.count <= 1) {
+        return 1;
+    }
+    __block NSUInteger frameCount = 1;
+    __block UIImage *previousImage = animatedImages.firstObject;
+    [animatedImages enumerateObjectsUsingBlock:^(UIImage * _Nonnull image, NSUInteger idx, BOOL * _Nonnull stop) {
+        // ignore first
+        if (idx == 0) {
+            return;
+        }
+        if (![image isEqual:previousImage]) {
+            frameCount++;
+        }
+        previousImage = image;
+    }];
+    
+    return frameCount;
+}
+
 - (BOOL)sd_isAnimated {
     return (self.images != nil);
 }
@@ -87,6 +108,19 @@
     }
 }
 
+- (NSUInteger)sd_imageFrameCount {
+    NSRect imageRect = NSMakeRect(0, 0, self.size.width, self.size.height);
+    NSImageRep *imageRep = [self bestRepresentationForRect:imageRect context:nil hints:nil];
+    NSBitmapImageRep *bitmapImageRep;
+    if ([imageRep isKindOfClass:[NSBitmapImageRep class]]) {
+        bitmapImageRep = (NSBitmapImageRep *)imageRep;
+    }
+    if (bitmapImageRep) {
+        return [[bitmapImageRep valueForProperty:NSImageFrameCount] unsignedIntegerValue];
+    }
+    return 1;
+}
+
 - (BOOL)sd_isAnimated {
     BOOL isAnimated = NO;
     NSRect imageRect = NSMakeRect(0, 0, self.size.width, self.size.height);

Tests/Tests/SDAnimatedImageTest.m

@@ -770,7 +770,10 @@ static BOOL _isCalled;
         [[SDImageCodersManager sharedManager] addCoder:[SDImageAWebPCoder sharedCoder]];
         UIImage *image = [UIImage sd_imageWithData:[NSData dataWithContentsOfFile:[self testMemotyCostImagePath]]];
         NSUInteger cost = [image sd_memoryCost];
+#if SD_UIKIT
         expect(image.images.count).equal(5333);
+#endif
+        expect(image.sd_imageFrameCount).equal(16);
         expect(image.scale).equal(1);
         expect(cost).equal(16 * image.size.width * image.size.height * 4);
         [[SDImageCodersManager sharedManager] removeCoder:[SDImageAWebPCoder sharedCoder]];

Tests/Tests/SDCategoriesTests.m

@@ -59,6 +59,7 @@
     image = [UIImage sd_imageWithGIFData:data];
     expect(image).notTo.beNil();
     expect(image.sd_isAnimated).beTruthy();
+    expect(image.sd_imageFrameCount).equal(5);
 }
 
 #pragma mark - Helper

Tests/Tests/SDImageCoderTests.m

@@ -435,7 +435,7 @@ withLocalImageURL:(NSURL *)imageUrl
     }
 }
 
-- (NSArray *)thumbnailImagesFromImageSource:(CGImageSourceRef)source API_AVAILABLE(ios(11.0), tvos(11.0), macos(13.0)) {
+- (NSArray *)thumbnailImagesFromImageSource:(CGImageSourceRef)source API_AVAILABLE(ios(11.0), tvos(11.0), macos(10.13)) {
     NSDictionary *properties = (__bridge_transfer NSDictionary *)CGImageSourceCopyProperties(source, nil);
     NSDictionary *fileProperties = properties[(__bridge NSString *)kCGImagePropertyFileContentsDictionary];
     NSArray *imagesProperties = fileProperties[(__bridge NSString *)kCGImagePropertyImages];